Product OverviewLow Rho SMD Series for Circuit Protection in Space-constrained Mobile Applications

The low rho (low-resistance) SMD series addresses the need in the consumer-driven mobile device market for a low-cost, low-power-consumption circuit protection solution for today’s increasingly compact products.

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APPLICATIONS

Battery pack PCMs used in compact consumer devices such as:

• Mobile and smart phones

• Media players (MP3/MP4)

• Digital still and video cameras

• Tablets

• Mini notebooks

BENEFITS

• Help save board space and power consumption and therefore costs, in space-constrained mobile electronics

• Are more compact in comparison with similar offerings and are available in an industry-standard form factor

• Can be assembled with a reflowable soldering technique, as opposed to the spot welding process required by many other components

KEY FEATURES

• Device resistance of 10 to 25 milliohms,

as compared to the 15~30 milliohm

industry standard

• Maximum electrical rating:

Voltage 6VDC and

short circuit current 50A

• Industry-standard form factor of

1210 (3.0mmx2.54mm; or 0.12inx0.10in) or

1206 (3.0mmx1.52mm; or 0.12inx0.06in) or

1812 (3.0mmx4.57mm; or 0.12inx0.18in)

• Useful for an operating current of 2A

and above

• All form factors have an R1MAX of

10 to 25 milliohms

• Useful for and packaged for surface

mounting on the PCB

The low rho SMD (surface-mount device) series is designed for space-constrained

mobile applications. The devices can help provide both overcurrent and overtemperature

protection for battery pack PCMs (protection circuit modules) used in compact consumer

devices such as smartphones and MP3/MP4 media players. In particular, the low rho

SMD series helps battery pack suppliers achieve their design goals and simplify their

installation methods.

The low rho SMD series comprises nine devices. In the model number descriptions, the

“micro” prefix refers to the 1210 form factor, the “nano” prefix refers to the 1206 form factor,

and the “mini” prefix refers to the 1812 form factor. All form factors have an R1MAX of 10 to

25 milliohms (see “Electrical Characteristics” table).

At a specified temperature and current, the devices in the low rho SMD series will trip after

a specified time interval and, by cutting the power supply, will enable overcurrent and

overtemperature protection.

Low rho SMD device resistance is just 10 to 25 milliohms, as compared to the 15~30 milliohm

industry standard. The devices’ lower resistance helps reduce power consumption and

improves battery efficiency.

DESIGN CONCEPT

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Low Rho SMD Series

UL, TUV, CSA

ELECTRICAL CHARACTERISTICS

DIMENSIONS IN MILLIMETERS

AGENCY RECOGNITIONMATERIALS INFORMATION

Part Number

IH IT VMAX IMAX PD MAX Max Time-to-Trip RMIN R1MAX

(A) (A) (VDC) (A) (W) (A) (S) (Ω) (Ω)

microSMD190LR 1.90 4.90 6 50 1.00 9.50 4.00 0.006 0.021

microSMD200LR 2.00 5.00 6 50 1.00 9.50 4.00 0.006 0.021

microSMD250LR 2.50 5.20 6 50 1.00 9.50 5.00 0.005 0.018

microSMD350LR 3.50 9.00 6 50 1.00 9.50 10.00 0.0025 0.011

microSMD450LR 4.50 9.00 5 50 1.00 25.00 2.00 0.002 0.008

nanoSMD175LR 1.75 5.00 6 50 1.00 9.50 1.00 0.008 0.025

nanoSMD200LR 2.00 6.00 6 50 1.00 9.50 3.00 0.006 0.024

nanoSMD270LR 2.70 6.30 6 50 1.00 8.00 5.00 0.005 0.018

nanoSMD350LR 3.50 6.30 6 50 1.00 8.00 5.00 0.004 0.018

nanoSMD500LR 5.00 10.00 6 50 1.00 25.00 2.00 0.002 0.008

Part Number

A B C D EFigure Marking

min. max. min. max. min. max. min. max. min.

microSMD190LR 3.00 3.43 0.50 1.00 2.35 2.80 0.25 0.75 0.076 LR2 -

microSMD200LR 3.00 3.43 0.50 1.00 2.35 2.80 0.25 0.75 0.076 LR2 T

microSMD250LR 3.00 3.43 0.50 1.00 2.35 2.80 0.25 0.75 0.076 LR2 L

microSMD350LR 3.00 3.43 0.50 1.00 2.35 2.80 0.25 0.75 - LR1 P

microSMD450LR 3.00 3.43 0.50 1.00 2.35 2.80 0.25 0.75 0.076 LR2 H

nanoSMD175LR 3.00 3.43 0.50 1.00 1.37 1.85 0.25 0.75 - LR1 J

nanoSMD200LR 3.00 3.43 0.50 1.00 1.37 1.85 0.25 0.75 - LR1 T

nanoSMD270LR 3.00 3.43 0.50 1.00 1.37 1.85 0.25 0.75 - LR1 L

nanoSMD350LR 3.00 3.43 0.50 1.00 1.37 1.85 0.25 0.75 - LR1 P

nanoSMD500LR 3.00 3.43 0.50 0.80 1.37 1.85 0.25 0.75 - LR1 H

RoHS Compliant

Directive 2002/95/ECCompliant

ELV Compliant

Directive 2000/53/ECCompliant

Pb-Free

PbHalogen Free*

HF* Halogen Free refers to: Br≤900ppm, Cl≤900ppm, Br+Cl≤1500ppm.

C

Marking

D

D

E

B

A

A

E

C

B

D

A

C

BC

Marking

D

D

E

B

A

A

E

C

B

D

A

C

B

Figure LR2Figure LR1

Notice:

Information furnished is believed to be accurate and reliable. However, users should independently evaluate the suitability of and test each product selected for their own applications. Littelfuse products are not designed for, and shall not be used for, any purpose (including, without limitation, military, aerospace, medical, life-saving, life-sustaining or nuclear facility applications, devices intended for surgical implant into the body, or any other application in which the failure or lack of desired operation of the product may result in personal injury, death, or property damage) other than those expressly set forth in applicable Littelfuse product documentation. Warranties granted by Littelfuse shall be deemed void for products used for any purpose not expressly set forth in applicable Littelfuse documentation. Littelfuse shall not be liable for any claims or damages arising out of products used in applications not expressly intended by Littelfuse as set forth in applicable Littelfuse documentation. The sale and use of Littelfuse products is subject to Littelfuse Terms and Conditions of Sale, unless otherwise agreed by Littelfuse.

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Low Rho SMD Series